The recent installation and commissioning of a sixth and final Jenbacher containerised landfill gas engine generator at UK Waste Management’s Risley 4 landfill site in Warrington, Cheshire, fulfils the NFFO 4 contract agreed in 1997 to supply a power capacity of just over 6MW. Knowsley-based Clarke Energy, the UK’s exclusive distributor of Jenbacher engines, has supplied six model JGC 320 GS – L.L containerised engines, each delivering 1MW, in three separate phases going back to last October. These purpose-designed engines, particularly adept at handling significant variations in landfill gas methane levels, have consistently proved themselves in these type of constant duty base load operations as Chris Parry, Landfill Processes Manager at Risley 4 explains, “We have an environmental responsibility to select the most fuel-efficient engines which operate to the highest European emission standards and Jenbacher engines provide consistent efficiency and durability. Their first engine units have now been commissioned at Risley 4 for some six months and are offering an availability of over 97% which is exceptional.”
Risley 4, UK Waste Management’s latest north west landfill gas generation scheme, covers a plan area in excess of 60 hectares and is currently taking waste at a rate of 700,000 tonnes each year. The total amount of gas currently being extracted from 50 permanent and some 170 temporary shallow wells is 3,200 cubic metres per hour, but it is predicted that at peak the site could produce up to 6,000 cubic metres per hour.
In terms of the Jenbacher engines, additional performance assurance is provided by the state of the art DIA.NE computer control system which is fitted to the Jenbacher models and operates, monitors and protects the system in its entirety. The remote monitoring control facility allows Clarke Energy to monitor the Risley 4 operations back at its Knowsley headquarters and implement round the clock preventative maintenance whenever necessary.
Risley 4 is the latest UK Waste Management landfill site in which Clarke Energy has been involved. It follows earlier projects at Chadderton and Holiday Moss, near St. Helens. May 1999 It is estimated that, once full, the Risley 4 landfill site will hold some 8 million tonnes of waste, and whilst the initial landfill gas contract is for 15 years, UK Waste Management intends to carry on generating from the site as long as it is economically viable to do so.
